WASHINGTON – After last week’s blog appeared, I got an e-mail from an old friend. The subject line said it all: “A Marathon? ARE YOU NUTS!”

I must explain here that I have known this guy since I was 12-years-old. And, as he reminded me, I wasn’t exactly a “jock” in high school.

So, am I crazy?

On days like this, when the heat index is in the stratosphere and I’m pondering lacing up my running shoes, I think he may have a point.

And so I talked to George Buckheit, head coach of the Capital Area Runners, a local running club. He acknowledged what I already knew — that training in the Washington summer can be a pain in your glutes.

George told me that even highly experienced athletes have trouble with it. They go out in the heat and then complain that their speed is way off. He said it doesn’t matter if your favorite exercise is walking around the neighborhood or running a marathon — when it’s this hot and humid, you have to slow down.

That’s because your body is working overtime to keep cool in the muck.

“At any given pace, you are probably going to be anywhere 10 to 20 beats (per minute) higher in heart rate,” George explained.

“So the effort is going to be much greater to run what would be your typical running pace.”

Now, I’m not a great fan of the treadmill, nor is George. But he told me on Code Orange or Code Red air quality days, “it’s not a bad idea to use the treadmill as an alternative to going outside.”

But if you do insist on braving the summer elements, exercise outdoors very early or very late, aim for shade and be sure to get lots of fluids. Or, as my doc Susan Bennett always tells me, “hydrate, hydrate, hydrate.”

So what am I doing this morning? I’ve got my water bottle, my iPod and I will run in air conditioned comfort.